抛光渣体系发泡陶瓷的发泡性能研究

以工业上成熟的抛光渣体系配方制备发泡陶瓷,探讨了烧结温度对其发泡性能的影响。同时,与外加发泡剂的抛光渣体系发泡陶瓷试样的显微结构、线收缩和体积膨胀率进行了对比分析,探讨了孔结构对发泡陶瓷试样强度和热稳定性的影响。研究发现,抛光渣具备一定的发泡能力,自身可发泡形成尺寸为10~200 μm(1 160~1 220 ℃)的球形气孔结构,孔壁的结构较致密。其对烧结温度十分敏感,在1 180~1 200 ℃范围内,发泡陶瓷试样的体积膨胀了2倍。外加SiC发泡剂能显著提高抛光渣体系发泡陶瓷试样的发泡能力,使其气孔尺寸增加10倍左右,但气孔形状不规则,孔壁结构中存在微小气孔。研究结果表明,外加发泡剂后,抛光渣自身发泡形成的壁孔结构使发泡陶瓷气孔率增加,强度损失较少,导热系数降低,且壁孔结构中的气孔分布不均匀,使发泡陶瓷的热稳定性降低。

Foaming Properties of Ceramics Foamed by Polishing Slag System

Foamed ceramics were prepared by commercially formula of polishing slag system, and the effects of sintering temperature on foaming properties of samples were studied. By contrastive analysis, the microstructure, linear shrinkage rate and volume expansion rate of samples with foaming agents were reseached, and the effects of pore structure on the strength and thermal stability were studied. It was found that, polishing slags can foam by itself, forming spherical pores with size of 10 μm to 200 μm (1 160 ℃ to 1 220 ℃). And the walls of pores were dense. It is very sensitive to sintering temperature, in the range of 1 180 ℃ to 1 200 ℃, the volume of the foamed ceramics sample expanded twice. The foaming property of samples with SiC was significantly improved, the pores were irregular, and the pore size of samples increased by 10 times. After adding foaming agent, There were small pores in the pore wall, which made the strength and the thermal conductivity loss less, while the porosity increased. However, the distribution of pores in the wall was uneven, decreasing the thermal stability of the foamed ceramics.